A standard myotomy and myectomy has been performed for relief of left ventricular outflow tract obstruction secondary to asymmetric septal hypertrophy in 340 patients. Fifty additional patients have been operated upon and an attempt has been made to tailor the operative approach depending on septal thickness, distribution of hypertrophy, level of systolic anterior motion contact of septum and concomitant coronary artery disease. Intraoperative ECHO's have been performed on 6 patients, providing precise data utilized intraoperatively. Patients with concomitant CAD may represent a higher risk for VSD creation which may be avoided by a modified left ventricular myotomy-myectomy or mitral valve replacement. Hemodynamic assessment of 25 of the last 50 patients operated upon reveals relief of the resting gradient in the majority of patients studied postoperatively, but persistent provocable gradients in a significant number of patients who may require medical therapy regardless of symptomatic status.